Narrative:

FAA inspector on board was conducting a cabin route inspection and was seated in passenger cabin for the flight. After the flight, the inspector questioned our use of oxy masks when one of us was absent from the flight deck. He thought he saw the pilot remaining at the controls not wearing his oxy mask. Our company apparently misinterpreted the FARS or misprinted the policy for supplemental oxy to be used in this case only above FL350 and issued this as a revision in company operations manual. They have since revised it again to above FL250 as stated in far 121. Far 91 still states use required above FL350 only. These numerous revisions have caused confusion as to what is required by FARS.

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Original NASA ASRS Text

Title: ACR FLT CREW ACCUSED OF OPERATING ABOVE FL250 WITH ONLY ONE PLT IN THE COCKPIT AND HE WAS NOT USING OXYGEN.

Narrative: FAA INSPECTOR ON BOARD WAS CONDUCTING A CABIN RTE INSPECTION AND WAS SEATED IN PAX CABIN FOR THE FLT. AFTER THE FLT, THE INSPECTOR QUESTIONED OUR USE OF OXY MASKS WHEN ONE OF US WAS ABSENT FROM THE FLT DECK. HE THOUGHT HE SAW THE PLT REMAINING AT THE CTLS NOT WEARING HIS OXY MASK. OUR COMPANY APPARENTLY MISINTERPRETED THE FARS OR MISPRINTED THE POLICY FOR SUPPLEMENTAL OXY TO BE USED IN THIS CASE ONLY ABOVE FL350 AND ISSUED THIS AS A REVISION IN COMPANY OPS MANUAL. THEY HAVE SINCE REVISED IT AGAIN TO ABOVE FL250 AS STATED IN FAR 121. FAR 91 STILL STATES USE REQUIRED ABOVE FL350 ONLY. THESE NUMEROUS REVISIONS HAVE CAUSED CONFUSION AS TO WHAT IS REQUIRED BY FARS.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.